It seems like Google is rolling out new, colorful UX for Assistant Voices. Google has rolled out six new voices to Google Assistant after this year's Google I/O, back in May, and the UX was not exactly the prettiest out there, so a change was expected. Well, Droid Life managed to get its hands on the preview of the new UX for Google Voices, and it looks a lot better than the current one, that's for sure.
Google still did not release an official confirmation or announcement, but the source says that this new voice picker UX has already started rolling out, yesterday, to be exact. Do keep in mind that it is rolling out to US users, and it will not become available to every single one of you straight away, this rollout is staged, as expected. The source says that the new UX is filled with "randomly selected colors", but the voice of your choosing will be automatically mapped to a color, the moment you select it. If you'd like to check out whether this new color picker is available for your device this very moment, head over to Google Assistant's Explore screen, then hit 'Settings'. After that, select 'Preferences', and 'Assistant Voice'. You should be seeing the same thing that is shown in the provided, if not, your device has not been updated with such functionality just yet, and you'll have to wait.
It is still unknown when will Google start rolling out this new UX to consumers outside of the US, but we're presuming it will happen in the near future, as soon as the company is convinced that there are no significant bugs to fix. You can always try connecting your phone to the internet via a VPN app, select the US as your country of choice, and see what happens, you may even get the update ahead of time if you don't live in the US.